We are requesting funds to purchase a CYTOMATION MoFlo flow cytometer high-speed cell sorter for the Wistar Institute core flow cytometry facility. This facility was established over 19 years ago. It is staffed by two experienced technicians and monitored by a faculty user committee. The core facility was last upgraded over 9 years ago with the purchase of an EPICS Elite Flow Cytometer. Many investigators at Wistar and in other institutions routinely use the cell sorting services for their scientific work. However, we are currently limited in our ability to provide high yields of limited cell populations within operational hours. In addition, there has been an increase in users requiring cell sorting in their NIH- sponsored research. We propose to upgrade our core facility by purchase of a CYTOMATION MoFlo flow cytofluorimeter to be used for a variety of NIH- sponsored projects, including cellular immunology, differentiation, control of cell growth, gene therapy, and tumor biology.